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Hot Water Boiler Extrol and Fill Valve


Could someone tell me if the pressure setting of the fill valve (Watts SB1156F) and the charge pressure of the Extrol tank should be the same or how should it be set up. The valve came preset to 15 psi and the tank (size 60) is precharged to 12.

The house is a two story cape with only one zone.




  • SWEI
    SWEI Member Posts: 7,356
    edited June 2013
    Both should be the same

    And set to the design pressure of the system.  15# is about right for a two story house -- unless the distance from the low point of the system to the high point is over 23 feet.

    Design pressure (minimum) = distance between those points times 0.434 plus 5 pounds.
  • Old_Navy_BT
    Old_Navy_BT Member Posts: 2

    No more dripping relief valve.
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